/* 功能性样式，刻意保持简单 —— 先跑通，不做视觉打磨。 */
:root {
  --bg: #14161a;
  --card: #1c1f26;
  --line: #2b303a;
  --fg: #e6e8ec;
  --dim: #9aa2b1;
  --accent: #4da3ff;
  --warn: #ffb454;
  --mono: ui-monospace, SFMono-Regular, Menlo, monospace;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 24px 16px 64px;
  background: var(--bg);
  color: var(--fg);
  font: 15px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", sans-serif;
}

header, main { max-width: 1000px; margin: 0 auto; }
header { margin-bottom: 20px; }

.headrow { display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; }
.lang select { width: auto; margin-top: 0; padding: 6px 10px; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }
h1 { font-size: 22px; margin: 0 0 4px; }
h2 { font-size: 14px; margin: 0 0 12px; color: var(--dim); font-weight: 600; text-transform: uppercase; letter-spacing: .04em; }
.sub { margin: 0; color: var(--dim); }

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 16px;
  margin-bottom: 14px;
}

.hint { color: var(--dim); font-size: 13px; margin: 8px 0 0; }
.mono { font-family: var(--mono); font-variant-numeric: tabular-nums; }

/* ---------- drop ---------- */
.drop {
  border: 2px dashed var(--line);
  border-radius: 10px;
  padding: 32px 16px;
  text-align: center;
  margin-bottom: 14px;
  transition: border-color .15s, background .15s;
}
.drop.over { border-color: var(--accent); background: rgba(77,163,255,.08); }
.drop p { margin: 0 0 6px; }

button {
  font: inherit;
  color: var(--fg);
  background: #262b34;
  border: 1px solid var(--line);
  border-radius: 7px;
  padding: 8px 14px;
  cursor: pointer;
}
button:hover:not(:disabled) { background: #2f353f; }
button:disabled { opacity: .45; cursor: default; }
button.primary { background: var(--accent); border-color: var(--accent); color: #06131f; font-weight: 600; min-width: 116px; }
button.primary:hover:not(:disabled) { background: #6cb4ff; }
button.link { background: none; border: none; color: var(--accent); padding: 0; text-decoration: underline; }

/* ---------- status ---------- */
.statusline { display: flex; justify-content: space-between; gap: 12px; margin-bottom: 8px; font-size: 14px; }
.bar { height: 6px; background: #2b303a; border-radius: 3px; overflow: hidden; }
.barFill { height: 100%; width: 0%; background: var(--accent); transition: width .12s linear; }

/* ---------- transport ---------- */
.row { display: flex; align-items: center; gap: 14px; }
#time { color: var(--dim); font-size: 13px; }
input[type=range] { width: 100%; margin: 12px 0 0; accent-color: var(--accent); }

/* ---------- segmented mode switch ---------- */
.segmented { display: flex; gap: 8px; flex-wrap: wrap; }
.segmented button { flex: 1 1 180px; padding: 12px 10px; }
.segmented button.active { background: var(--accent); border-color: var(--accent); color: #06131f; font-weight: 600; }

/* ---------- controls ---------- */
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; }
label { display: block; font-size: 13px; color: var(--dim); }
select { display: block; width: 100%; margin-top: 6px; font: inherit; color: var(--fg); background: #262b34; border: 1px solid var(--line); border-radius: 7px; padding: 8px; }
#boostVal { color: var(--fg); }

/* ---------- visualization ---------- */
canvas { width: 100%; height: auto; display: block; border-radius: 6px; background: #0b0d10; }
canvas.spectrum { margin-top: 8px; }     /* 播放头处的实时频谱，紧跟在瀑布图下面 */
.meters { display: flex; gap: 28px; margin-top: 12px; flex-wrap: wrap; align-items: flex-end; }
.bitratePick { margin-left: auto; }          /* 右下角 */
.bitratePick select { width: auto; margin-top: 4px; }
.meters .k { color: var(--dim); font-size: 13px; display: block; }
.meters .v { font-size: 15px; }

/* ---------- info ---------- */
.kv { display: grid; grid-template-columns: max-content 1fr; gap: 6px 20px; font-size: 14px; }
.kv dt { color: var(--dim); }
.kv dd { margin: 0; font-family: var(--mono); font-variant-numeric: tabular-nums; }
.kv dd.good { color: #6ee7a8; }
.kv dd.bad { color: #ff7b7b; }

.warn {
  margin-top: 12px;
  padding: 10px 12px;
  border-radius: 7px;
  background: rgba(255,180,84,.1);
  border: 1px solid rgba(255,180,84,.35);
  color: var(--warn);
  font-size: 13px;
}
.warn + .warn { margin-top: 8px; }
.warn.bad { background: rgba(255,123,123,.1); border-color: rgba(255,123,123,.4); color: #ff9c9c; }

a { color: var(--accent); }